1. Field of the Invention
The present invention relates generally to the field of connectors for testing integrated circuits. More specifically, the present invention discloses a connector that can be attached to an integrated circuit in any of a plurality of orientations to accommodate access or space limitations on the circuit board.
2. Statement of the Problem
It is often difficult to obtain clear access to an integrated circuit package for testing after it has been installed on a circuit board. It is often particularly difficult to attach the test equipment connector in the proper orientation to the integrated circuit package given tight space limitations. This problem is further compounded in situations where the circuit board is connected in a three-dimensional arrangement with other circuit boards. One solution in the past has been to use a conventional connector with a long flexible cable extending to the test equipment. This approach may suffice in some circumstances, but suffers from the ultimate limitation that sufficient space must be available to attach the connector to the integrated circuit in the proper orientation. In addition, the length of the cable can result in excessive loading of the integrated circuit output leads.
A number of types of contacts and probes have been invented in the past for testing integrated circuits, including the following:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Prevost 4,993,954 Feb. 19, 1991 Evans, et al. 4,975,638 Dec. 4, 1990 Whann, et al. 4,837,622 June 6, 1989 Owens, et al. 4,830,623 May 16, 1989 Whann, et al. 4,757,256 July 12, 1988 ______________________________________ Holsopple, et al., "Increased Useable I/O Pins On a Substrate", IBM Technical Disclosure Bulletin (Vol. 23, No. 7A, Dec. 1980).
Prevost discloses a device for interconnection between an integrated circuit and an electrical circuit. The desired interconnections are provided by stacked insulating platelets. Each platelet is crossed by a number of conducting channels, either with or without offset.
Evans, et al., disclose a test probe assembly to test integrated circuits. The device includes a contactor formed of flexible film material having probe contacts formed on the undersurface in a pattern matching contacts of the integrated circuit.
The patents to Whann, et al., disclose a high density probe card for test equipment to contact and test unsevered large scale integrated circuit dies formed on a semiconductor wafer. The probe card uses a probe array having an annular form with two sets of wire probes arranged in two interleaved conical patterns.
Owens, et al., disclose a connector arrangement for electrically interconnecting first and second arrays of pad-type contacts.
Holsopple, et al., disclose a device which increases the useable number of I/O pins for a silicon chip 12 mounted on an upper substrate member 10. The upper substrate member 10 is connected by an array of pins 24 and 26 to a lower substrate member 14 bearing a similar pattern of contacts and pins 16 and 18. Selected pins are electrically connected by metal lines 22.
3. Solution to the Problem
None of the prior art references uncovered in the search show a connector assembly that can be engaged to the integrated circuit package in any of a number of possible orientations to accommodate space and access limitations on the circuit board, while maintaining the order of the connections from the integrated circuit leads to the test equipment. In addition, the present invention includes a transition board that permits the connector assembly to be readily interfaced to test equipment using any of a variety of different contact patterns.